IdeaWell

Project ideas from Hacker News discussions.

GrapheneOS says Pixel 11 has MTE support after all

Original Article

Hacker News Discussion

📝 Discussion Summary (Click to expand)

Three prevalent themes in the discussion

  1. MTE causes instability and performance concerns
    Users note that enabling Memory Tagging Extension leads to frequent app and system‑service crashes (MTE‑SIGSEGV) and adds measurable overhead, making the phone feel unstable to end‑users.

    “The main issue is that apps and services crash when an MTE segfault occurs. So this means that to the uninformed end user apps appear spuriously unstable with no meaningful context.” – OneDeuxTriSeiGo
    “Four bits per 16 bytes means a 3 % increase in memory needed… hardware overhead for checking tags… and software overhead of setting/changing/clearing tags as necessary.” – wat10000

  2. Google’s decision to disable/downgrade MTE on Pixel 11 (cost‑saving or hardware errata)
    Several commenters argue that Google intentionally turned off MTE to save money or because of suspected CPU errata, marking a regression from earlier Pixel devices that did use the feature.

    “Apparently to save money.” – user_7832 (referring to the disabling of MTE)
    “The thread makes it sound like it could have been disabled due to errata or performance issues… the software Google is shipping intentionally doesn't use MTE on the Pixel 11 hardware.” – protimewaster
    “Nothing is wrong. They just don't use MTE yet… they wanted to save some costs until they will use MTE, so they removed some hardware acceleration and downgraded the GPU.” – worldsavior

  3. Debate over GrapheneOS’s niche status and its role in pushing security
    The conversation frequently circles on whether GrapheneOS represents a niche hobbyist project or a necessary security‑focused alternative, with praise for its technical rigor and criticism of its communication style.

    “My personal attitude to Graphene seems to get a bit more negative with each one of these 'rants' and I doubt I'd go far out of my way to help them…” – amaccuish
    “They are good enough to have their own Cellebrite column. If they complain about something, you should probably listen.” – matheusmoreira
    “People that flash custom Android OSs are the very definition of niche users…” – timschmidt (counter‑argued by others who see privacy/security as a mainstream expectation).

🚀 Project Ideas

Generating project ideas…

MTE Crash Reporter

Summary

  • Library that intercepts MTE SIGSEGV, collects tag info and stack traces, and sends reports to a backend without crashing the app.
  • Enables developers to identify and fix memory safety bugs in production.

Details

Key Value
Target Audience Android app developers using native code (NDK)
Core Feature Signal handler for SIGSEGV with SEGV_MTESERR/SEGV_MTEAERR, extracts fault address, tags, and uploads via HTTPS
Tech Stack C/C++ for native library, Java/Kotlin wrapper, protobuf, optional backend (e.g., Google Cloud Functions)
Difficulty Medium
Monetization Revenue-ready: SaaS per‑app monthly fee

Notes

  • HN commenters complained that MTE causes apps to crash with no useful context (OneDeuxTriSeiGo: “apps just crash when you happen to do some particular action leaving you walking on your toes”).
  • Provides the missing crash‑reporting bridge that Google could use to push fixes, addressing the desire for “register a global signal handler to capture these MTE SIGSEGVs and report them back”.

MTE Debugger UI

Summary

  • Desktop GUI that connects over adb to run an app under MTE in asynchronous mode, logs every tag mismatch as a non‑fatal event, and visualizes offending allocations.
  • Helps developers reproduce and fix MTE violations without dealing with app crashes.

Details

Key Value
Target Audience Mobile native‑code developers, ROM maintainers (e.g., GrapheneOS)
Core Feature Runs target process with PTrace or LD_PRELOAD wrapper that intercepts malloc/fork, tags allocations, and logs mismatches to UI
Tech Stack Electron/React frontend, Rust daemon for ptrace, Android NDK bindings, adb over TCP
Difficulty High
Monetization Hobby (open‑source) with optional paid support/consulting

Notes

  • Commenters noted the need for “a way to set sampling rates to zero or very low for application versions that have been identified as a known problem” and wanted tooling to generate crash dumps (toast0).
  • This UI gives developers a safe sandbox to see all MTE violations, reducing the “spurious crashes” pain point and encouraging fixes.

MTE Hardware Validation Suite

Summary

  • Automated test suite that runs on a device to verify MTE synchronous and asynchronous behavior, checks for CPU errata, and produces a compliance report.
  • Useful for ROM projects like GrapheneOS to decide whether to enable MTE on new hardware.

Details

Key Value
Target Audience Custom ROM developers, OEM validation teams, security researchers
Core Feature Series of stress tests (buffer overflow, use‑after‑free, tag collisions) in both sync and async modes, compares observed traps vs expected, logs discrepancies
- Tech Stack C++ test harness, Fastboot/adb for device control, Python orchestrator, JSON report
Difficulty Medium
Monetization Hobby (could be sponsored by ROM foundations)

Notes

  • GrapheneOS engineers expressed concern that “MTE may actually be broken due to CPU errata” and wanted independent verification (multiple Google engineers unable to give info).
  • A validation suite gives them concrete data to decide about enabling MTE, directly addressing the uncertainty and the desire for “comprehensive test … to see if it's usable”.

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